This invention is drawn to the field of vacuum cleaners, and more particularly, to a novel dual filter wet/dry hand-held vacuum cleaner.
Wet/dry hand-held vacuum cleaners are portable devices useful in home, office and other environments to provide pick-up of dirt and/or liquid spillage. When not in use, they are typically stored, together with any accessories, on a recharging base unit. U.S. Pat. No. 4,831,685 issued May 23, 1989 to Bosyjl et al., incorporated herein by reference, is exemplary of the heretofore known wet/dry hand-held vacuum cleaners.
The more times they are used, and the longer they are operated each time, the greater is the dirt and/or liquid spillage that accumulates therewithin until the point is reached beyond which the cleaning power of the units is noticeably reduced. At each such time, whether after multiple small cleaning jobs or during a single large one, the units must be emptied of the accumulated grime.
Wet/dry hand-held vacuum cleaners are thus called upon to provide filtration effective to accumulate solid and liquid matter, to provide such filtration for as long as possible before their cleaning power is noticeably reduced and, at the times of emptying, to provide efficient clean-up.
Accordingly, it is the principal object of the present invention to disclose a novel dual filter wet/dry hand-held vacuum cleaner effective to provide liquid and/or dry pick-up while minimizing the frequency with which it needs cleaned out that, at cleanup time, may be cleaned efficiently with little or no mess.
The dual filter wet/dry hand-held vacuum cleaner of the present invention includes a powered unit; an elongated dust bowl removably attached to the powered unit having an intake nozzle that discharges a stream in which dirt and/or liquids may be entrained; a first filter mounted in the dust bowl that receives the intake nozzle stream and discharges filtered air from which liquids and comparatively-large particulates that may be present in the intake nozzle stream have been separated; and a second filter intermediate the first filter and the powered unit that receives the filtered air from the first filter and discharges purified air from which comparatively-small particulates that may be present in the filtered air have been separated. The dual filter wet/dry hand-held vacuum cleaner of the present invention in this manner provides effective filtration of liquids and solids and thereby provides-clean, healthy environments that are substantially free of dirt, dust, allergens and bacteriological pollutants.
Because the first filter separates liquids and such comparatively-large particulates as dirt particles, lint, hair and dead skin from the intake nozzle stream, the second filter is allowed to remove such comparatively-small particulates as pollen, other allergens and fine dust from the filtered air without becoming clogged by comparatively-large particulates, which maximizes the collection efficacy of the second filter and therewith minimizes the frequency with which it needs cleaned or replaced.
The first filter preferably includes a frame slidably mounted in the dust bowl that is substantially coextensive with a major portion thereof. The frame substantially coextensive with the dust bowl maximizes the particulate trapping capacity of the first filter and therewith minimizes the frequency when it needs to be cleaned out.
The frame of the first filter preferably has top, and open bottom, side and end walls that bound an interior volume. One end wall is adapted to receive the intake nozzle so that it opens into the interior volume of the frame of the first filter. Metallic screens are mounted to the open side and bottom walls that separate comparatively-large particulates and liquids from the intake nozzle stream, and the other open end wall of the frame provides a discharge end. At emptying time, the accumulated dirt may be discharged from the interior volume and through the open discharge end of the frame of the first filter directly into a suitable trash receptacle, which minimizes dust generation and direct user contact with dirt. Any liquid that passes through the side and bottom screens is accumulated in the dust bowl, which, at cleanup time, may be separately discharged by emptying the dust bowl into a suitable liquid receptacle.
The second filter preferably includes a cover removably attached to the powered unit; a flange providing a flat filter mounting recess formed about the dust bowl receiving face of the powered unit; and one of a foamed plastic flat filter, a HEPA flat filter and a ULPA flat filter that is removably mounted to the mounting recess of the powered unit. At cleaning or replacement times, the flat filter mounted in the filter mounting recess may be readily removed, and cleaned or replaced.
Any suitable filter arrangement to separate comparatively-large and comparatively-small particulates from the intake nozzle stream and any suitable seal arrangement to provide fluid-tight first and second filter fluid communication and to prevent dirt and liquid ingress from the dust bowl to the powered unit may be employed.